The month of October is the eighth least rainy month in terms of rainfall. The month of November receives good rains. The average rainfall pan India for the month of October is 81mm.
We know that the Southwest Monsoon starts around June 1 and ends by September 30. Though the rains continue for some more parts post Southwest Monsoon as well, states like East Uttar Pradesh, Bihar, Jharkhand, West Bengal, Maharashtra, Chhattisgarh and Odisha receive rains on a receding note.
The Northeast Monsoon starts around October 1 and ends by December. These rains start to recede by the second half of this month. At that point of time, South Peninsula receives minimal rains.
In the month of October, no significant weather activity takes place in the Northwest plains of the country. By this time, some weather activity starts in the hills but this time we didn’t see any major activity up there in the hills.
Irrespective of the arrival of Northeast Monsoon on time, South India did experience good spell of rain in the month of October. Otherwise, October is generally tagged as one of the lean months for rain.
There is a lot of variability in these two streams of Southwest Monsoon and Northeast Monsoon. They are based upon their arrival, strength etc. It is like when the Southwest Monsoon recedes, it is the arrival time for Northeast Monsoon. There are times when some areas are largely rain deficit and some are largely rain excess.
Statistically, rain deficit is more than normal rainfall. This year, in the month of October, all the 4 regions were rain deficit. The most rain deficit region was Northwest India with 77% deficiency and least deficit was South Peninsula with 41%. Further pockets which are largely rain deficit are Bihar with 73%, Uttarakhand, Rajasthan, Gujarat, Madhya Pradesh and Maharashtra with more than 90%. Andhra Pradesh, Telangana and Karnataka also performed poorly with deficiency exceeding 50%.
Odisha and Kerala are the only two pockets which behaved normally. Odisha has been a consistent performer since many years. This year, Odisha was rain surplus by 8% and Kerala by 4%.
| Year | Average(mm) | Normal(mm) | Departure (%) |
| 2011 | 38.1 | 80.9 | -53 |
| 2012 | 58.6 | 80.9 | -27 |
| 2013 | 129.3 | 80.9 | +60 |
| 2014 | 60.0 | 80.9 | -26 |
| 2015 | 42.3 | 80.9 | -48 |
| 2016 | 54.5 | 80.9 | -33 |
| 2017 | 81.5 | 80.9 | +1 |
| 2018 | 35.6 | 80.9 | -56 |
Image Credit: wikipedia
Please Note: Any information picked from here must be attributed to skymetweather.com
